This invention relates to methods and apparatus for securing communications over a network, and more particularly to a method and apparatus for limiting receiver access to the communication.
With the increased use of computer networks to carry communications there is an increasing need for securing communications. For example, it is well known for a sender to encrypt an e-mail communication, which the receiver then decrypts. It also is known to provide a secure communication channel in which server computers encrypt all data along the channel regardless of the efforts of the sender to encrypt or not encrypt the communication.
In these known secured communication methods the end user receives either an encrypted or unencrypted message. If encrypted, the user has some manner of decrypting the communication. For example, the user typically has possession of a decryption key. Once the message is received the user stores and accesses the encrypted, unencrypted and/or decrypted message at their desire. These known methods assume that either the receiver is trustworthy, or that the receiver is the one who would be harmed by free disclosure of the information (rather than the sender or some other party). For example, in public key cryptography the receiver can decrypt the message as many times as desired and store the message in an unencrypted form. Thus, the receiver gets control of the received information. As the applications for network communications grow, there are many types of transactions to be handled over a network. In some it may be preferable not to assume the receiver will maintain the security of confidential information. Accordingly, there is a need to provide security which limits the receiver's access to received communications.